Corneal Defects and Stem Cell Therapeutics

Cornea is the most anterior segment of the eye that provides exquisite vision. This is transparent outermost surface of the eye, consisting of a stratified epithelium, a collagenous stroma and an innermost single-cell layered endothelium. Cornea is an important visual structure assists in providing a clear vision by refracting light onto the lens, which in turn focusing on the retina. It is a vital tissue that remains poorly protected from the environment and face toxic dust and heat exposure. Cornea acts as a major protective shield to the eye and represents two thirds of its refractive power. It is made up of a tough transparent tissue admitting and focusing light in the eye. The cornea has a secondary protective function, it control light, and is able to screen out ultraviolet light. It also serves to physically protect the eye by shielding it from germs and small particles. Cornea is located over the pupil, iris, and the anterior chamber. All of these are very delicate components which are vitally important to sight. Cornea contains self-renewal cells which possess enormous regeneration capacity. The cornea is able to recover quickly from minor scratches, but deeper scars can cause the cornea to lose transparency and impede vision (Table 1).